Cube bread into 1/2 inch cubes. Spread cubes evenly over baking sheet. Let dry 2 days or until cubes lose moisture and become hard. Melt butter in large skillet. Pour butter from skillet into a bowl. Add onion salt, parsley and dillweed; mix well. Reheat skillet in which butter was melted. Add croutons; distribute evenly over skillet surface. Pour melted-butter mixture over croutons. Stir to distribute evenly. Fry croutons until golden brown and thoroughly heated; cool. Store up to 1 month in airtight container. Yields 2 quarts.